Preheat oven to 375°F. Heat the 1 tbsp oil in a skillet over medium heat. Add the onion and cook, stirring occasionally, until soft and lightly golden, 5 to 7 minutes.

Stir in the tomato sauce, chili powder, cumin, garlic powder, onion powder, and salt. Bring to a simmer, then cook on low for 5 minutes. Remove from heat.

In a bowl, mix the chicken, sour cream, 1 cup of the cheese, and ½ cup of the warm sauce.

Spread a thin layer of sauce in a 9x13‑inch baking dish. Warm the tortillas (wrap in damp paper towel, microwave 30‑45 seconds). Spoon filling down the center of each, roll snugly, and place seam‑side down in the dish.

Pour the remaining sauce over the enchiladas and top with the remaining 1 cup cheese. Bake 20 to 25 minutes until bubbly and golden. Let rest 5 minutes, garnish with cilantro, and serve.